


Crumb’s Worldbuilding Headcanons (currently ABO dynamics only)

by crumbcake



Category: Multi-Fandom, Voltron: Legendary Defender
Genre: Alpha/Beta/Omega Dynamics, Alpha/Omega, Alternate Human Biology, Alternate Universe - Human, F/F, F/M, M/M, Non-Traditional Alpha/Beta/Omega Dynamics, Supporting Text for ABO Fanfiction, Worldbuilding
Language: English
Status: Completed
Published: 2018-08-12
Updated: 2018-09-01
Packaged: 2019-06-26 08:00:23
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,812
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15659076
Author URL: https://archiveofourown.org/users/crumbcake/pseuds/crumbcake
Summary: Ch 1 contains my worldbuilding version of ABO (alpha/beta/omega) mechanics. My Alternate Universe ABO sexuality version is derived and influenced by other fans’ headcanons and also from reading up on the interesting variety of sexual reproduction in the animal kingdom. Earth biology is so varied, weird and amazing - love exploring how sexuality and reproduction could’ve been different for us humans. You are very welcome to use this headcanon (just let me know as I would love to read!!)





	1. Chapter 1

**Author's Note:**

> This is not a fanfic but rather supporting background text for fanfic content. I’ve added Voltron as a fandom tag because I currently write exclusively in that fandom and I’m writing these mechanics for a future ABO Voltron fic I’m planning but hopefully I can use this for any additional future ABO (post my 3KK voltron fic which is different).
> 
> I’m sure I’m not the only fandom worldbuilding nerd out there so this is for my fellow worldbuilding wonks - hope you enjoy! :)
> 
> Also an obvious warning that this is a worldbuilding work of fiction - in other words its all made up!!!

**ABO Genetic Details**

 

46XX - female or intersex (true hermaphrodite omega)

46XY - male or intersex (true hermaphrodite omega)

 

In my ABO both XX and XY chromosome pairings _commonly_ contain both gender characteristics in some form. These are the most common genetic manifestations:

 

  * Male alphas have 46xy chromosomes containing the following genes: dominant male genes,  female genes that are mostly recessive and alpha genes.
  * Female alphas have 46xx chromosomes containing the following genes: dominant female genes, male genes that are mostly recessive and alpha genes.
  * Male omegas have 46xy chromosomes containing the following genes: dominant female AND male genes; omega genes,  typically male phenotype expression (they look male and have more male hormones however their reproductive organs are equally both)
  * Female omegas have 46xx chromosomes containing the following genes: dominant female AND male genes, omega genes, typically female phenotype expression (they look female and have more female hormones however their reproductive organs are equally both)


  * Male betas have 46xy chromosomes that contain _no female genes and have trace to no amounts of alpha or omega genes._
  * Female betas have 46XX chromosomes containing no _male genes and have trace to no amount of alpha or omega genes._



 

_Betas are less common (though not rare) in the population and tend to have lower fertility rates or cannot reproduce._

 

All dynamics are verified at birth. Omega dynamic and male or female gender for alpha/beta dynamics are visually obvious. Blood tests verify alpha/beta/omega dynamic and identifies omega gender.

 

**Dynamics Biology Details**

 

Omega details: 

Omegas have fully functional male and female sexual organs though testicles are typically cohesively part of the vaginal mound and penises are smaller than alphas. They cannot impregnate themselves as omegas’ bodies switch reproductively to either male or female fertility depending on heat type (details further below). An individual omega’s own sperm and own eggs contain hormones that destroy each other although there have been exceptionally rare cases of asexual fertilization where the fetus is a near clone or suffers severe developmental disabilities. Typically these embryos do not survive and break down during pregnancy causing menstruation.

 

Omega Heat cycles: 

Omegas generally have cyclical heats anywhere between 2 to 4 a year. Only omegas have heats. All heats consist of:

  * Copious vaginal slick occurrence throughout a heat, regardless of heat type.
  * Plateau/Surge waves during a heat-


    * Plateaus are time periods during a heat where an omega experiences low to moderately high states of arousal.



 

    * Surges are time periods during a heat where an omega experiences an intense near frantic need to copulate. Omega/Alpha heats will include the urge for knotting. An omega’s vaginal opening will typically relax then dilates (degree of dilation varies) involuntarily (often distressing for an omega experiencing a first knotting) until the omega is knotted. When knotted the omega's vaginal opening will initially constrict tightly then gradually relax until the omega regains muscular control. Omegas biological imperative during a surge adversely impacts higher cognitive functioning.



 

    * A word on sexual consent during a heat: International law recognizes heat surges as mentally compromised states in where omegas cannot consent to sex. Surge/plateaus periods may not be entirely clear as such local consent laws differ in defining when consent is possible. Many local laws state that consent for heat sex must occur prior to true hormonal heat. Contested heat rape cases in a court of law often include the establishment of date and time of consent in comparison to the results of contemporaneous blood tests that establish date and time of hormonal heat. All rape kits for all dynamics must include blood tests determining the victim’s hormonal levels.



 

Omega Heat Types: 

There are four types of heats that can occur depending on external pheromones that an omega is exposed to:

1\. Beta heat (2 - 5 days)- nearly all heats start out this way and remain this way if an omega is not exposed to alpha pheromones.

  * Male omega will have fertile ejaculations, typically not ovulate, and experience strong biological urge for sex though no urge to be knotted
  * Female omega will ovulate, typically have sterile ejaculations, and a strong biological urge for sex though no urge to be knotted



 

2\. Omega heat (2 - 5 days)- Beta heat becomes an omega heat when an omega is exposed to alpha male rut pheromones.

  * Omega heat triggers omega ovulation and an omega experiences a strong biological urge to be knotted. Omega ejaculate becomes sterile within a short period of exposure to alpha male rut.
  * Male alpha sperm will travel to the fallopian tube and attempt to fertilize the ovulated egg. If successful egg fertilization, the omega’s womb will thicken and prepare environment for the pregnancy within a week. Omegas only menstruate if pregnancy breaks down or no fertilized egg implantation occurs.



 

3\. Alpha heat (2 - 5 days)- Beta heat becomes an alpha heat when an omega is exposed to alpha female rut pheromones. Omega ejaculate becomes fertile and typically omega ovulated egg breaks down within a short period of exposure to alpha female rut.

  * Alpha heat - triggers a false-rut where an omega experiences strong biological urge to penetrate their partner followed by a strong need to be knotted. 
  * Omega womb releases pheromones to lead fertilized alpha egg and additional attached omega sperm towards the fallopian tube. If ovulation occurred during a beta heat, the female alpha pheromones triggers an omega’s body to breakdown the omega egg which is discarded bloodlessly as there is no womb tissue build up at that stage.
  * The presence of fertilized eggs in the Fallopian tubes triggers the womb to thicken and prepare for pregnancy. If successful egg implantation in the womb, Omega becomes pregnant. Omegas only menstruate if pregnancy breaks down or none of the fertilized eggs have implanted.



 

4\. There is also Shared heat (1 - 3 days) - Exposure to other omegas can trigger beta heat which shortens any type of heat for the omegas. During a shared heat, the time between heat surges (increased/frantic need to copulate) is prolonged and plateaus (time between surges) rarely occur simultaneously for the omegas.

An example of plateau/surge heat cycle with two omegas involved (plateau = no to moderately high arousal while surge = overwhelming arousal):

  1. Omega A and B plateau
  2. Omega A surges while Omega B plateaus,
  3. Omega A plateaus and Omega B remains in plateau
  4. Omega B surges and Omega A remains in plateau
  5. Omega B plateaus and Omega A remains in plateau



 

  * Side note: Shared heats are reported as socially beneficial to omegas and extremely pleasant experiences (some omegas have described the experience as ‘what exposure to catnip seem to feel like for some cats’). Alpha presence may trigger alpha/omega heat for all omegas present depending on biological compatibility and bond/relationship with the alpha. Shared heat will not lessen the strength of omega surges if the omega is strongly bonded to the alpha though the plateaus remain prolonged.


  * In many cultures, it is commonly accepted social behavior for multiple (depending on culture, 2 or more) omegas to share an alpha or beta heat. The dominant culture deems acceptable two or three partnered pairings where the third partner is an additional omega. Omega-omega relationships are not expected to share a heat (referred to as betamega heats) with a third omega partner though this trio combination is not as socially stigmatized as it was historically.



 

Alpha details: 

Only alphas have ruts which are triggered exclusively by exposure to an omega’s heat (so an alpha would never experience a rut if never exposed to an omega in heat). Strength of a rut depends on nature/nurture elements such as hormonal compatibility to omega, the alpha’s emotional state and overall health. Alphas cannot get pregnant nor menstruate.

 

Male rut - the knot (near the base of an erection) becomes enlarged during a rut. A rut triggers increased sperm generation and the strong urge to penetrate and knot (the knot expands generously during orgasm - think round base long neck shaft for the overall penis shape). Ruts induce sustained erections and multiple sustained ejaculations during a knotting.

 

Female rut - the knot (clitorus/urethra combination) becomes enlarged and protrudes during a rut. A rut triggers ovulation of many alpha eggs (unlike omega ovulation of a singular egg) and a strong urge to be penetrated. If the alpha’s partner ejaculates inside the female alpha, she will eventually experience a strong urge to knot her partner. Her knot will expand generously (think round base stubbed neck shaft for the overall clitorus shape) when the alpha is ready to ejaculate. Ruts may induce sustained knotting and multiple alpha ejaculations.

 

_ What happens during an Alpha heat (an omega with a female alpha)?  _

 

Omega ejaculates inside an alpha female where seminal fluid meets ovifluid while sperm find eggs to fuse with (weaker eggs are destroyed by this). The combined fluid now oviseminal fluid collects inside the alpha’s pseudo-womb and eventually induces the strong urge to knot. The knotting causes the alpha to ejaculate through the urethra, propelling the sperm and egg collected within the psuedo-womb area into the omega via psuedo-womb contractions (often reported as pleasant).

 

The released fertilized ovum along with omega sperm that have stuck but not fused to the ovum swim towards the omegas cervix (assisted by omega contractions during orgasm as well as homing hormones within the womb) and reach the fallopian tube. The zygote remains there while the womb prepares for the pregnancy. Many of the zygotes are destroyed by the omega sperm still attempting to fuse while cell division occurs. During that time zygotes travel back down the womb ( 9 - 10 days) and implants. Successfully implanted zygote will create a protective layer for itself and release hormones that will cause the uterus to become a hostile environment for other zygotes (occasionally others survive).

 

Beta details: 

Betas have non-alpha/beta sexuality.

Beta male penis do not have knots. A significant population of beta males are infertile or have medium to low fertility.

Fertile beta females experience monthly ovulation/menstrual cycles. A significant population of beta females are infertile or have medium to low fertility.

 

**Reproductive Cells & Organ Information **

 

Sperm: 

Alpha male - quantity over quality. Its theorized that the knot ensures more sperm can make it through.

Omega - quality over quantity. Omega have less sperm in their ejaculate however sperm are more aggressive and more powerful swimmers than alpha male sperm.

 

Ovulation: 

Alpha female - quantity and quality - tougher eggs than omega egg, eggs have a coating that sperm attach easily to and allow swift travel back into the omega and better implantation.

Omega  - singular egg during ovulation

Rapid ovulation triggered by heat often causes brief sharp pain during the first day of the heat for the omega.

 

Knot: 

Female knot includes urethra area. Knotting locks in the omega during forceful and copious ejaculation of oviseminal fluid.

 

Male knot is bigger than female knot and locks in the omega during copious ejaculation of less hardy sperm via deep penile penetration.

 

Omegas tend to easily orgasm from a knotting and have the urge to ‘milk’ the knot inside, squeezing and squirming on the knot which stimulates the alpha into orgasming multiple times when knotting.

 

Pheromones: 

Pheromones are an integral part of alpha/omega dynamics as well as beta in lesser form. Pheromones trigger ruts and different heat manifestations and have a direct impact on impregnation. Social bonds have a pheromone component in some form for all dynamics - omegas are known to experience an alpha or omega heat without an initial beta heat if they are bonded to an alpha dynamic partner. Omegas exposed to other omegas are known to experience prolonged heat plateaus and retain more mental acuity during surges.

 

**Pregnancy**

 

Alphas and Male Betas cannot become pregnant (cannot carry)

Omegas and Female Betas can become pregnant (can carry).

 

Omega males gain biologically female physical characteristics during pregnancy such as pelvis expansion, breast development and breast milk production. The female characteristics begin to revert once breast milk production stops though the male omega may not fully return to biologically masculine characteristics depending on age and number of pregnancies.

 

 

**ABO Reproduction Chart (Which couples can reproduce?)**

Link to an image version of table below:

[ABO Reproduction Chart (Image)](https://vintagefanship.tumblr.com/image/176913040433)

(Apologies for the formatting, AO3 does not allow borders for tables hence the URL link above to the image version!)

 

  | 

**Male Alpha**

**(cannot carry)**

| 

**Male Beta**

**(cannot carry)**

| 

**Male Omega**

| 

**Female Alpha**

**(cannot carry)**

| 

**Female Beta**

| 

**Female Omega**  
  
---|---|---|---|---|---|---  
  
 

**Female Alpha**

 

| 

 

No [No rut]

 

| 

 

 

No [No rut]

 

 

| 

 

Yes (extremely high chance) - Omega carries alpha egg, omega sperm.[Rut triggered knotting.]

 

| 

 

No [No Rut]

 

| 

 

No [No rut]

 

| 

 

Yes (extremely high chance) - Omega carries alpha egg and omega sperm. [Rut triggered knotting.]

   
  
 

**Female Beta**

 

| 

 

Yes (med-low chance) -

Female beta carries [No rut]

 

| 

 

Yes (low chance) - Female beta carries [No rut]

 

| 

 

Yes (medium chance) - Female beta carries [No rut]

 

| 

 

 

No [No rut]

 

 

| 

 

 

No [No rut]

 

 

| 

 

Yes (rare, if fertile ejaculation occurs) - Female beta carries. [No rut]

   
  
 

**Female Omega**

 

| 

 

Yes (very high chance) - Omega carries [Rut triggered knotting.]

 

| 

Yes (medium chance) - Omega carries [No rut]

| 

 

Yes (extremely high chance) - Female Omega carries male omega sperm and female omega egg - fraternal twins likely [No rut]

 

| 

 

Yes (extremely high chance) - Omega carries alpha egg and omega sperm. [Rut triggered knotting.]

 

| 

 

Yes (rare, if fertile ejaculation occurs) - Female beta carries. [No rut]

 

| 

 

Yes (rare, if fertile ejaculation occurs) [No rut]

   
  
 

**Male Alpha**

 

| 

 

 

No [No rut]

 

 

| 

 

 

No [No rut]

 

 

| 

 

 

Yes (very high chance) - Omega carries omega egg and alpha sperm. [Rut triggered knotting.]

 

| 

 

 

No - [No rut]

 

 

| 

 

Yes (med-low chance) - Female beta carries - [No rut]

 

| 

 

Yes (very high chance) - Omega carries omega egg and alpha sperm.[Rut triggered knotting.]

   
  
 

**Male Beta**

 

| 

 

 

No [No rut]

 

 

| 

 

 

No [No rut]

 

 

| 

 

Yes (rare chance,  if omega ovulates) [No rut]

 

| 

 

 

No [No rut]

 

 

| 

 

Yes (low chance) - female beta carries [No rut]

 

| 

 

Yes (medium chance) - Omega carries [No rut]

   
  
 

**Male Omega**

 

| 

 

Yes (very high chance) Omega carries omega egg and alpha sperm. [Rut triggered knotting.]

 

| 

 

Yes (rare chance,  if omega ovulates) [No rut]

 

| 

 

Yes (rare chance, if one of the omegas ovulates) [No Rut]

 

| 

 

Yes (extremely high chance) - Omega carries alpha egg, omega sperm. [Rut triggered knotting.]

 

| 

 

Yes (medium chance) - Female beta carries [No rut]

 

| 

 

Yes (extremely high chance) - Female Omega carries male omega sperm and female omega egg - fraternal twins likely [No rut]

   
  
 

 


	2. ABO 3KK Flavor

**Summary for the Chapter:**

> My 'verse rules for my ABO Three Kids Klance series. :)

**Gender and Dynamic Identity** -

There are 4 main hormones in abo sexuality, everyone has testosterone and estrogen. The level of testosterone determines gender. Omegas have no alpha hormones. Alphas have no omega hormones. Low levels of either or both alpha and omega hormones or none at all mean the subject is a beta. Alpha hormones exceeding threshold mean the subject is an alpha. Omega hormones exceeding threshold means the subject is an omega.

**All about Omegas -**

Omegas tend to physically look like betas or look androgynous and are the biologically intersexed members of this AU human society. Most omegas are true hermaphrodites though pseudohermaphroditism to varying degrees is also commonplace (Keith’s biologically male reproductive parts stopped developing further at puberty - he’s mostly sterile as far as male fertility). An omega’s male/female gender is initially determined from testosterone levels in blood tests.  

Only omegas experience heat. Heats occur anywhere from 1 to 3 times a year and are 2-3 days long. They tend to be predictable. Doesn’t happen when omegas are pregnant.

During a heat, the inner vaginal opening swells and becomes very pliable as the omega’s body responds to their partners pheromones. Male alpha partner causes acute relaxation of the internal vaginal canal (alpha male penis usually more than makes up for this relaxation) and the strong urge for knotting (rectum relaxes involuntarily). Female alpha partner causes the strong urge to penetrate for the omega (pseudo-rut) and then an even stronger urge to be knotted (rectum relaxes involuntarily) and knot stimulation (grinding down). The relaxed omega’s vaginal canal descends during stimulation, pressing down and breeching around the knot so ejaculate would flow directly into the vaginal canal and not the rectum. 

Omegas have scent glands located on their necks that also swell and become sensitive when heat approaches. 

A heat without an alpha partner causes the strong biological urge for sex  (need to penetrate and/or be penetrated) but does not trigger the need to be knotted unless the omega is biologically bonded to a partner that has alpha hormones  (alpha dynamic partner and in some cases beta dynamic if they have enough alpha hormone) and has been exposed to the hormone for a long time. Keith would have the urge for a knot even if Lance was not around since he has been with him and exposed to his hormones for so long. 

Male omegas pee via their penis (Keith does) and females via their vaginal urethra. All omegas have sealed external birthing slits as well as an inner vaginal opening via the rectum. Womb pressure and pheromones cause the inner vaginal entrance to seal over during late pregnancy and the external birthing slit to relax in preparation for baby delivery.  Anal canal pressure cause vaginal passageway to constrict away during a bowel movement. Vaginal fluids (slick) keeps the inner vaginal opening sanitized and further sanitizes the rectum area and lubricates when the omega is aroused.

Pregnancy causes omega bodies to gain more feminine characteristics, wider hips and breast development along with milk production. Omegas menstruate only after a heat if conception occurred but the pregnancy becomes not viable and breaks down or after childbirth (get rid of all the womb/uterus build up). 

**All about Alphas -**

Alphas tend to look hyper feminine/masculine; this physical change tends to occur during late teen/young adult stage (19-21). Ruts are a supplemental impregnating mechanism for alphas. All ruts are triggered by  exposure to compatible omega heat though there is a nature and nurture component to this. Alphas only knot during a rut (impregnating mechanism). Ruts cause prolonged arousal and knotting as well as the ability to orgasm multiple times while knotting. 

Female alpha ruts initially trigger pseudo-ruts for omegas where omegas penetrate the female alpha first followed by alpha’s urge to knot and omega’s urge to be knotted. For a female alpha, the urethra and clitoris area swells and protrudes when aroused at any time but swells acutely (the knot) during a rut. When knotting an omega the female alpha ejaculates oviseminal fluid consisting of her eggs being ‘escorted’ by omega’s latched on sperm as they travel towards the omega’s fallopian tube. 

The male knot is located at the base of a male alpha’s penis . The female knot has a tapered tip (urethra) that is under an inch in length. 

All alphas experience a massive increase/surge of alpha hormones during puberty. 

**All about Betas -**

Betas do not have knots. They have moderate fertility rates as a group. Each beta may have varying degrees of alpha and/or omega hormones that typically do not exceed alpha/omega dynamic thresholds. Beta males tend to look masculine but not as hyper masculine as alpha males while beta female tend to look feminine but not as hyper feminine as alpha females.  Their sex organs are like our world. Female betas menstruate regularly if fertile. 

Betas with alpha hormones may rut in the sense of prolonged arousal and stamina but no knotting if exposed to an omega heat. Betas never have enough omega hormones to have their own heat and never have enough alpha hormones to trigger the urge for knotting if they have an omega partner. (exceptions occur though tiny % of the population).

**ABO Society  and Misc -**

The majority of the population prefer other dynamics with varying flexibility/preferences on physical attributes and gender though the biggest biological attraction is scent/pheromone compatibility. Clara has shown a strong preference for omega boys in particular. She would probably say she likes omega males, omega females, beta female in that order. She’s not wild about beta men and is not sexually attracted to her own dynamic.

Scent oriented society – Adults and teenagers pick up on pheromonal scents, omegas slightly more than others. Each dynamic tends to have similar base scents. Scents gain various characteristics and vary in potency depending on the subject’s mood and stress. Looks and scent clue people in on dynamic.

Male/Female gender for non-omega babies and Omega dynamic are the easiest to determine visually at birth. Blood tests will determine a non-omega baby’s dynamic as well as an omega baby’s gender.

Adult betas and omegas that have not given birth can be confused for one another visually though scent will identify their dynamic (though omegas often look more androgynous). 

Children have a neutral scent that do not give away their dynamic (argued that their scent trigger need to nurture i adults) Children cannot sense pheromonal scents - conscious sensitivity to alpha/omega/beta scents develop during puberty.

Pregnancy - biologically possible for omegas and to a lesser extent female betas  (both are typically considered the ‘mom’). It is biologically impossible for alphas and male betas (they are typically considered the ‘dad’) to get pregnant. Twins are rare because strongest fetus cannibalizes the rest during pregnancy. Alphas cannot lactate. In an omega/omega relationship, the omega that carries would be considered ‘mom’. If Clara has biological children she must have impregnated an omega (male or female). Clara would be considered the dad in the relationship.

Biological Bond - involves an omega mating/scent gland - Anyone that sucks on a receptive omega’s mating gland enough times will biologically bond with the omega (and probably get them super horny if they weren’t already). Biological bond means the couple becomes highly attuned and receptive to each others’ pheromones as well as gain additional  health benefits. It can fade. Sucking on mating gland also encourages omega ovulation / sperm production during a heat (happens anyway but increases quality/quantity.) 

Bondmate is the term for marriage and is used for mated couples whether there’s an actual biological bond (involve omega) or not (non-omega couple). There’s no “married”, there are bondmates, bonding ceremonies, bond wreckers, etc.

**Keith and Lance**

Keith’s dick stopped developing at the onset of puberty. He would’ve had trouble with a female alpha during a heat as a pseudo-rut would not have gone well for him without medical intervention. After his third pregnancy, Keith’s chest never fully flattened back to what it was (common for post childbirth male omegas) though his hips lost most of the pregnancy curve they had gained. He produces greater than average quantity of slick in general and is part of the smaller population of omegas that produce constant slick when exposed to their bondmate’s pheromones during pregnancy. It’s miserable for him but not so-secretly makes Lance feel very smug.

Lance was cute but not very alpha-looking until 21/22 which he made up for with all of his blustering. He was particularly attuned to pheromone scents before his injury. After his injury, he couldn’t sense pheromone scents though regular smells were fine if slightly dampened. 

**Author's Note:**

> Feel free to let me know what you think if you enjoy this kind of thing or you are welcome to share your variation so long as you are willing for other writers/readers to use your abo headcanon even if uncredited (and I might tweak mine if I like it and it works for my fics)! Thanks!


End file.
